Bone cells (human and bovine) have been utilized to 1) study the biosynthesis of extracellular matrix proteins such as collagen, osteonectin, bone proteoglycan and other bone proteins, and alterations of matrix production in the disease Osteogenesis Imperfecta; 2) study the responsiveness of the cells to a variety of hormonal and pharmacological factors such as parathyroid hormone and 1,25 dihydroxy vitamin D3; 3) elucidate production and interaction of potential growth factors such as transforming growth factor-Beta, and 4) serve as a source of mRNA and DNA for studies of these proteins at the genomic level.